The invention relates to coupling devices in general, and more particularly to improvements in coupling devices which can be utilized with advantage as clasps or catches on bracelets, necklaces and other articles of jewelry.
Clasps or catches are used on chains, necklaces, bracelets, watchbands, straps and other articles of jewelry to permit the establishment or termination of a separable connection. Reliability of such clasps or catches is of great importance, especially when used on expensive articles of gold, silver or platinum jewelry. Moreover, such coupling devices must have an eye-pleasing appearance and should be manipulatable with a minimum of effort and regardless of whether or not they are visible to the eyes of the user during engagement or disengagement of their separable parts. Many presently known clasps employ slidable, turnable pivotable and/or otherwise movable male parts in the form of pins, studs, hooks or arms which can be grasped by the nail of a finger or by two fingers for movement into or from engagement with an eyelet, a tube or another female part. Such conventional clasps are not entirely satisfactory, mainly because they cannot be readily manipulated when not in the field of vision, e.g., when a person wishes to release a clasp or catch at the back of her or his neck. An impatient person who is unable to rapidly engage or disengage a conventional clasp is likely to lose patience and to damage the clasp or is compelled to seek assistance from another person. Alternatively, the chain, bracelet, necklace or timepiece which is equipped with the clasp is not worn or remains on the body of the user at an inopportune time, e.g., when the user wishes to take a bath or to go to bed. German patent application No. 38 40 170 Al of Laatzen (published May 31, 1990) discloses a clasp which comprises a tubular female component and a male component having a laterally extending resilient arm. When the male component is inserted into the female component in a first angular position and is thereupon turned in the socket of the female component, the end face of its resilient arm is free to engage an internal surface of the female component and to thus prevent extraction of the male component. If the latter is to be extracted from the socket of the female component, at least one of the two components must be turned relative to the other component in order to disengage the end face of the resilient arm from the internal surface of the female component and to orient the male component in such a way that it can be pulled out of the socket. A drawback of the clasp which is disclosed by Laatzen is that the locking or retaining action of the female component is not sufficiently reliable. For example, one of these components can be accidentally turned relative to the other component to thus cause the male component to assume an angular position in which it can be extracted from the socket of the female component. Moreover, the person in charge of manipulating the clasp is not aware of the angular position of the male component in the female component, i.e., such person is not certain that the inserted male component is maintained in an angular position for withdrawal from the socket or in an angular position in which the end face of its resilient arm overlies the internal surface of the socket.